benchmarking tools

[David]

I have a bunch of redhat servers that I've been tasked with benchmarking over a period of time.   I need to be able to 
report cpu, ram, swap, disk io, network io usages, etc.   Pretty much all the basic performance metrics.

What do use or have you used to do this?  I'd prefer something that comes with the ability to do pretty graphs, reports of some
sort and is FOSS.

Thanks for any insights,
David

-- 
"I find your lack of faith disturbing."
--Darth Vader